1. Field of the Invention
This invention relates to vacuum cleaning, and in particular to vacuum cleaning surfaces closely adjacent to upright wall surfaces.
2. Description of the Background Art
In U.S. Letters Patent No. 2,324,111 of Alvin E. Ross, a suction nozzle is illustrated having an automatically retractable surface contacting brush element. A forwardly projecting spring is connected to the support for the leading brush element of the nozzle so that flattening of the spring when engaging the wall baseboard causes the mounting strip for the leading brush to move in an upward direction, causing the flow of air into the nozzle to be concentrated underneath the forward wall of the nozzle.
Gerald M. Magarian, in U.S. Letters Pat. No. 3,005,224, shows a vacuum cleaner having a pressure relief valve comprising a flap valve hung on a spring wire and pressed against the inner wall of the brush chamber for normally closing a plurality of relief openings in the front wall of the nozzle. In the event the subjacent carpeting is drawn into the normal nozzle suction opening so as to block off the air flow therethrough, the relief valve is opened by the suction pressure increase in the suction chamber, thereby limiting the vacuum in the chamber to a preselected value.
A problem arises in the cleaning of floor or carpet surfaces adjacent upright wall surfaces including vertical wall surfaces of cabinets, furniture, etc. in that it is difficult to maneuver the conventional vacuum cleaner nozzle fully to the upright wall, thus undesirably leaving dirt at the intersection between the floor and wall. This problem is aggravated by the provision of projecting bumpers and the like on the nozzle so that the downwardly opening suction chamber is spaced substantially from the upright wall, such as the baseboard thereof, in its closest disposition. One attempted solution to the problem has been to provide openings on the edge of the nozzle, permitting the user to clean adjacent the baseboard by moving the nozzle along the wall rather than toward and from the wall. Such movement, however, is not always available in close quarters, and the problem of removing the dirt from adjacent the upright wall remains a vexatious problem.